*4.4. Age*

Male age has been correlated with deterioration in ejaculated semen parameters and increased serum FSH concentrations [34]. It has been proposed that FSH increases secondary to decreased androgen production associated with aging [35]. However, since FSH is not predictive of sperm retrieval, as discussed above, age also should not be a predictive factor [28]. Age has been suggested to be a predictive factor in certain patient subsets, such as those men with Klinefelter Syndrome, but at our center, sperm retrieval rates for Klinefelter Syndrome patients in the oldest age group (>35 years) are still 50%. These observations do not provide compelling evidence for early sperm retrieval [36]. It has been our uncontrolled observation that in many men with severe oligozoospermia followed longitudinally using repeated semen analyses that it is rare for these men to progress to azoospermia during our observation period. Finally, while advanced paternal age has reported negative impact on outcomes in offspring (increased genetic risks), our experience has demonstrated no upper age limit (even men in their 80s) for successful sperm retrieval [37].
